The dimensional hierarchies used are “city
computer science
Description
Assignment
Suppose we define a data cube with three dimensions: place,
age, and salary.
The dimensional hierarchies used are “city < state <
region” for place, “age_value < age_category [20-30, 30-40, 40-50}” for age
and “salary_value < salary_class [50-60K, 60-65K, 65-70K]” for salary.
The measure monitored in the Fact Table is the Number of
Subscribers.
What is the total number of cuboids possible from this data
cube?
We have the following three materialized cuboids: Cuboid 1: {state} where age_category = 20-30
AND salary_class = 60-65K Cuboid 2:
{city, age_value} where salary_class = 60-65K
Cuboid 3: {region, salary_class} where age_category = 30-40
Which of the above three cuboids can be selected (i.e.
feasible) and, if there are more than one, which is the best among those to
process each of the following queries? and why? NOTE: For some queries, the
base cuboid may have to be selected.
(a) The query to be processed is {city, age_category} with
the selection constant “salary_class = 60-65K”.
(b) The query to be processed is {salary_class} with the
selection constant “age_value = 31”.
